LED glue sealing device, display unit and glue sealing method

Abstract

The invention relates to the technical field of LED glue sealing, and particularly provides an LED glue sealing device, a display unit and a glue sealing method. The LED glue sealing device comprises a pouring platform used for arranging a PCB (Printed Circuit Board) substrate of an LED display unit; a cup groove is formed in one side, far away from the pouring platform, of the PCB substrate, and an LED chip assembly is assembled in the cup groove and is in a state to be sealed with glue; the steel mesh is arranged above the pouring platform, and a first gap is kept between the steel mesh and the PCB substrate during glue sealing; the steel mesh is provided with a plurality of mesh holes penetrating through the steel mesh up and down, and each mesh hole corresponds to one cup groove during glue sealing and is used for guiding packaging glue into the corresponding cup groove; and the scraper is used for moving on the surface of one side, far away from the PCB substrate, of the steel mesh so as to sufficiently extrude packaging glue into each cup groove from meshes of the steel mesh, and glue sealing is carried out on the LED chip assembly. According to the LED glue sealing device, the display unit and the glue sealing method provided by the invention, the operation space, the stability and the efficiency of a small-spacing LED glue sealing process can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED sealing, and in particular to an LED sealing device, a display unit and a sealing method. Background Art

[0002] In recent years, with the expansion of production capacity at major LED packaging manufacturers, packaged device prices have continued to decline, leading to increasing industry concentration. The industry has entered a new phase characterized by a prominent oligopoly, large-scale lean production, and rapid technological advancement. High-quality development has become the primary direction for future advancement. Enhancing product value and gross profit margins is a key focus for LED packaging companies in their product development strategies, with fine-pitch and Mini LED devices currently attracting the most attention.

[0003] The current conventional sealing process for fine-pitch LED devices mainly involves dispensing, potting, and sealing. Dispensing utilizes the synergy of a motion controller and a dispensing controller to achieve automatic positioning and precise dispensing. When the device receives a dispensing instruction, the motion controller controls the movement of the X, Y, and Z axes to move the needle to the specified position. The dispensing controller then controls the needle to dispense the glue. This process has the following drawbacks:

[0004] Small operating space: The encapsulation glue formula is too thin and easy to flow, and the viscosity is too thick and easy to pull the glue and jam the valve core;

[0005] Poor stability: The dispensing needle used for small-pitch products has a small diameter, which has a certain impact on the bubble discharge action when the cavity is first used. At the same time, the syringe pressure control, the accuracy of the screw and pull rod, and the number of cavity needles all affect the uniformity of glue discharge;

[0006] Low efficiency and high risk: For small-pitch device products like QFN, the number of single pieces is large, and it takes about 3 minutes to dispense one piece of material, and nearly 30 minutes to dispense a box of material (10 pieces / box). In order to prevent general epoxy glue from absorbing moisture when exposed to the air, it must be baked within 30 minutes after dispensing.

[0007] Currently, no effective solutions have been proposed to the above problems existing in the existing fine-pitch LED encapsulation process. Summary of the Invention

[0008] The embodiments of the present invention provide an LED sealing device, a display unit, and a sealing method, which at least solve the problems of small operating space, poor stability, and low efficiency in the existing fine-pitch LED sealing process.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] In the first aspect, the present invention provides an LED sealing device, comprising: a pouring platform for setting a PCB substrate of an LED display unit; the PCB substrate has a cup groove on a side away from the pouring platform, an LED chip assembly is assembled inside the cup groove and is in a state to be sealed; a steel mesh is arranged above the pouring platform and maintains a first gap with the PCB substrate during sealing; the steel mesh is provided with a plurality of mesh holes running through the upper and lower parts thereof, each mesh hole corresponding to a cup groove during sealing, and is used to introduce the packaging glue into the interior of the corresponding cup groove; a scraper is used to move on the surface of the steel mesh away from the PCB substrate to fully squeeze the packaging glue from the mesh holes of the steel mesh to the interior of each cup groove to seal the LED chip assembly.

[0011] Preferably, the spacing between adjacent meshes of the steel mesh is the same as the spacing between adjacent cup grooves of the PCB substrate, and the size of the mesh is larger than the size of the corresponding cup groove.

[0012] Preferably, the mesh holes are square holes or circular holes, and the cup grooves are circular grooves; the center line of each mesh hole coincides with the center line of the corresponding cup groove.

[0013] Preferably, the scraper is a plastic scraper having a bidirectional blade.

[0014] Preferably, it also includes: the pouring platform is provided with a vacuum adsorption mechanism and a positioning component; the positioning component is arranged on the working surface of the pouring platform and corresponds to the steel mesh marking point, and is used to align with the substrate marking point of the PCB substrate during sealing and to make the cup groove of the PCB substrate correspond one-to-one with the mesh of the steel mesh; the vacuum adsorption mechanism is arranged on the working surface of the pouring platform, and is used to adsorb the PCB substrate to be brushed with glue on the pouring platform to ensure pouring accuracy.

[0015] Preferably, it also includes: a steel mesh mounting frame, which is arranged above the casting platform and is used to install the steel mesh; a steel mesh adjustment mechanism, which is arranged above the casting platform and connected to the steel mesh mounting frame and is used to adjust the gap between the steel mesh and the PCB substrate to the first gap.

[0016] Preferably, it also includes: a scraper mounting frame, which is arranged above the steel mesh mounting frame and is used to install the scraper; a scraper driving mechanism, which is arranged on the scraper mounting frame and is used to drive the scraper to move along the length, width and height of the steel mesh to adjust the position of the scraper and brush glue.

[0017] In a second aspect, the present invention provides an LED display unit, which is applied to the aforementioned LED sealing device, comprising: a PCB substrate; the PCB substrate comprises a plurality of PCB substrate units; the PCB substrate unit comprises: a prepreg and a PCB circuit board; the prepreg is arranged on a side of the PCB circuit board having a solder pad, and a through hole is provided at a position of the prepreg corresponding to the solder pad, and the through hole of the prepreg cooperates with the PCB circuit board to form a cup groove of the PCB substrate; an electrode sheet for connecting each LED chip assembly is provided on a side of the PCB circuit board away from the prepreg; the thickness of the prepreg is greater than that of the PCB circuit board.

[0018] Preferably, the thickness of the prepreg is 0.3 mm to 0.5 mm, and the thickness of the PCB circuit board is 0.16 mm to 0.36 mm.

[0019] In a third aspect, the present invention provides an LED sealing method, which is applied to the aforementioned LED sealing device, and includes the following steps: placing a PCB substrate assembled with an LED chip component and in a state to be brushed with glue with its cup groove facing upward on a casting platform, and making each cup groove of the PCB substrate correspond to a mesh hole of the steel mesh; adjusting the position of the steel mesh so that a first gap is maintained between the steel mesh and the side of the PCB substrate having the cup groove; pouring the packaging glue onto the surface of the steel mesh from the side of the steel mesh away from the PCB substrate; using a scraper to repeatedly move on the surface of the steel mesh to brush the packaging glue on the surface of the steel mesh flat, and allowing the packaging glue to fully enter the interior of each cup groove from the mesh holes of the steel mesh for brushing; removing the PCB substrate after brushing with glue from the casting platform and drying it to complete the LED sealing.

[0020] Preferably, the PCB substrate assembled with the LED chip assembly and in a state to be brushed with glue is placed on the casting platform with its cup groove facing upward, and each cup groove of the PCB substrate corresponds to a mesh hole of the steel mesh, including: aligning the substrate marking point of the PCB substrate assembled with the LED chip assembly and in a state to be brushed with the positioning component in the casting platform, and placing it on the casting platform with the cup groove facing upward, so that each cup groove corresponds to a mesh hole; wherein the position of the positioning component corresponds to the position of the steel mesh marking point; and adsorbing the PCB substrate assembled with the LED chip assembly on the surface of the casting platform by the vacuum adsorption mechanism in the casting platform to ensure casting accuracy.

[0021] Preferably, a scraper is used to repeatedly move on the surface of the steel mesh to brush the packaging glue on the surface of the steel mesh flat, and ensure that the packaging glue fully enters the interior of each cup groove from the mesh holes of the steel mesh for brushing, including: planning the movement path of the scraper according to the position of the substrate marking point of the PCB substrate through the scraper driving mechanism; starting the scraper through the scraper driving mechanism to move on the surface of the steel mesh according to the set movement path until the packaging glue on the surface of the steel mesh is brushed flat, and the packaging glue enters the interior of each cup groove from the mesh holes of the steel mesh for brushing.

[0022] The beneficial effects of the present invention are as follows:

[0023] The present invention provides an LED sealing device, a display unit and a sealing method, which change the traditional LED sealing process from a dispensing method to a brushing method. By setting a steel mesh and a scraper, the packaging glue flows from the mesh holes of the steel mesh to the inside of each cup groove of the PCB substrate. Finally, the packaging glue on the surface of the steel mesh is evenly scraped by the scraper, so that the packaging glue fully enters the inside of the cup groove to complete the brushing operation. Compared with the dispensing method, the brushing process has low requirements on the viscosity of the glue, a large operating space and high efficiency. It can perform sealing operations on multiple PCB substrate units at the same time in batches, and is particularly suitable for the sealing operation of small-pitch LED devices. In addition, the packaging glue can flow evenly and smoothly into the inside of the cup groove of each PCB substrate unit, thereby improving its consistency and uniformity. The brushing process is less difficult to control, which makes the stability and display effect of the LED display unit better, thereby solving the problems of small operating space, poor stability and low efficiency in the existing small-pitch LED sealing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive effort.

[0025] Figure 1 Schematic diagram of the structure of the LED sealing device of the embodiment of the present invention;

[0026] Figure 2 This is a structural diagram of a PCB substrate to be sealed with glue of an LED display unit according to an embodiment of the present invention;

[0027] Figure 3 It is an embodiment of the present invention Figure 2 A local enlarged schematic diagram of point A in FIG;

[0028] Figure 4Schematic diagram of the structure of the steel mesh of the embodiment of the present invention;

[0029] Figure 5 This is a schematic structural diagram from a first angle of a PCB substrate unit to be sealed with glue according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic structural diagram from a second angle of a PCB substrate unit to be sealed with glue according to an embodiment of the present invention;

[0031] Figure 7 This is a schematic structural diagram of the PCB substrate unit after sealing according to an embodiment of the present invention;

[0032] Figure 8 It is a flow chart of an LED sealing method according to an embodiment of the present invention.

[0033] Reference numerals in the figures:

[0034] 1. Casting platform; 101. Lifting mechanism;

[0035] 2. PCB substrate; 201. Substrate marking point; 202. PCB substrate unit; 2021. PCB circuit board; 2022. Prepreg; 2023. Packaging glue; 2024. LED chip assembly; 2025. Solder pad; 2026. Electrode sheet;

[0036] 3. Steel mesh; 301, steel mesh marking points;

[0037] 4. Scraper;

[0038] 5. Steel mesh mounting frame;

[0039] 6. Steel mesh adjustment mechanism;

[0040] 7. Guide rails;

[0041] 8. Scraper mounting bracket;

[0042] 9. Scraper drive mechanism; 901. Z-axis drive mechanism; 902. X-axis drive mechanism; 903. Y-axis drive mechanism;

[0043] 10. Water platform. DETAILED DESCRIPTION

[0044] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0045] In the related art, the dispensing process is mainly used to perform the sealing operation on small-pitch LED devices. The dispensing process has high requirements for the viscosity of the glue. If the viscosity is too thin or too thick, it is not suitable for dispensing, which makes the glue operation space small. At the same time, the needle diameter used for dispensing small-pitch LED devices is small, which can easily affect the bubble discharge action when the cavity is first used. In addition, the dispensing operation has high requirements for needle pressure control, screw and pull rod accuracy, and the number of cavity needles. If the needle pressure control accuracy is poor or the number of cavity needles is inappropriate, the uniformity of the glue output will be affected, resulting in reduced stability. Because there are a large number of LED units on the small-pitch LED device, the LED units need to be dispensed one by one during dispensing, resulting in poor dispensing efficiency. It is possible that the packaging glue has absorbed moisture in the air and deteriorated before baking, thereby increasing the risk of the sealing operation.

[0046] like Figure 1 As shown, in order to improve the operating space, stability and efficiency of the small-pitch LED sealing process, the first embodiment of the present invention provides an LED sealing device, including: a casting platform 1, a steel mesh 3 and a scraper 4.

[0047] The casting platform 1 is used to set the PCB substrate 2 of the LED display unit. Figure 2 、 Figure 3 As shown, the PCB substrate 2 has a cup groove on the side away from the casting platform 1. The LED chip assembly 2024 is assembled inside the cup groove and is in a state ready for encapsulation. This state refers to the LED encapsulation process having completed the steps of dehumidification → die bonding (R → G → B) → baking → wire bonding → dehumidification. Next, the LED chip assembly and its bonding wires need to be encapsulated with encapsulating glue.

[0048] The steel mesh 3 is arranged above the casting platform 1 and maintains a first gap with the PCB substrate 2 during the sealing process. Figure 4 As shown, the steel mesh 3 is provided with a plurality of mesh holes running through the upper and lower parts thereof. When sealing, each mesh hole corresponds to a cup groove, and is used to introduce the packaging glue 2023 into the interior of the corresponding cup groove.

[0049] Among them, the first gap is set according to the sealing requirements. In order to prevent the packaging glue 2023 from flowing between adjacent cup grooves, it is necessary to ensure that the first gap is less than or equal to 0, and preferably less than 0, so that the steel mesh 3 applies a certain pressure to the PCB substrate 2.

[0050] The scraper 4 is used to move on the side surface of the steel mesh 3 away from the PCB substrate 2 to fully squeeze the packaging glue 2023 from the mesh holes of the steel mesh 3 into the inside of each cup groove to seal the LED chip assembly 2024.

[0051] The present invention provides an LED sealing device according to an embodiment of the present invention. By setting a steel mesh 3 and a scraper 4, the packaging glue flows from the mesh holes of the steel mesh 3 to the inside of each cup groove of the PCB substrate 2. Finally, the packaging glue on the surface of the steel mesh is evenly scraped by the scraper 4, so that the packaging glue fully enters the inside of the cup groove, completing the glue brushing operation.

[0052] Compared with the dispensing method, the brushing process has low requirements for glue viscosity, large operating space, and high efficiency. It can perform glue sealing operations on multiple PCB substrate units in batches at the same time. It is especially suitable for the sealing operation of small-pitch LED devices. Its efficiency is 5 times that of dispensing.

[0053] Furthermore, the encapsulation glue flows evenly and smoothly into the cup groove of each PCB substrate unit, improving its consistency and uniformity, and expanding the display viewing angle to meet different customer needs. The glue application process is easier to control, resulting in better stability and display quality for the LED display unit, and high added value.

[0054] like Figure 2 As shown, in a preferred but non-limiting embodiment of the present invention, the PCB substrate 2 includes a plurality of PCB substrate units 202 arranged in a matrix, and the multiple mesh holes on the steel mesh 3 are arranged in the same arrangement as the PCB substrate units, so that the spacing between adjacent mesh holes of the steel mesh 3 is the same as the spacing between adjacent cup grooves of the PCB substrate 2.

[0055] Furthermore, in order to allow the packaging glue 2023 to flow from the mesh into the cup groove and prevent the deformation or offset of the PCB substrate, which may lead to uneven packaging glue in the cup groove and poor LED display effect, the embodiment of the present invention preferably has a mesh size larger than the corresponding cup groove size, so that the packaging glue can fully flow into each cup groove of the PCB substrate, thereby improving the uniformity of the sealing glue.

[0056] Furthermore, the cup groove is preferably a circular groove, and the mesh hole can be a square hole or a circular hole, preferably a square hole, because when the side length of the square hole is the same as the diameter of the circular hole, the area of the square hole is larger, making the size of the square hole larger than the slot of the cup groove, which is conducive to filling the cup groove and avoiding the problem of uneven glue brushing due to deformation of the cup groove.

[0057] from Figure 4 From the perspective of viewing, the four inner corners of each mesh of the steel mesh 3 are chamfered to facilitate the packaging glue to enter the cup groove of the PCB substrate 2 from the mesh.

[0058] Furthermore, the centerline of each mesh coincides with the centerline of the corresponding cup groove, thereby ensuring the alignment accuracy of the sealant, so that the alignment accuracy and repeatability of the LED sealant device are ±12.5 um (±0.0005), and 6σ, Cpk is greater than or equal to 2.0.

[0059] In a preferred but non-limiting embodiment of the present invention, when a metal scraper 4 moves on the surface of the steel mesh, metal debris is easily generated, and the metal debris enters the encapsulation glue, causing the encapsulation glue to discolor and affecting the display effect. At the same time, considering that some non-metallic materials have poor flexibility and corrosion resistance, which easily damage the surface of the steel mesh, as well as the problem of high cost, the present invention preferably uses a plastic scraper 4 to ensure the glue brushing effect. In addition, the plastic scraper has a bidirectional blade, which can move back and forth and left and right to brush the glue, thereby improving the glue brushing efficiency.

[0060] In another preferred but non-limiting embodiment of the present invention, the pouring platform 1 is equipped with a vacuum suction mechanism and a positioning assembly. The positioning assembly is located on the working surface of the pouring platform 1 and corresponds to the stencil marking point 301. It is used to align the PCB substrate 2 with the substrate marking point 201 during the glue sealing process and to ensure that the cup grooves of the PCB substrate 2 and the mesh of the stencil 3 are aligned one-to-one. The vacuum suction mechanism is also located on the working surface of the pouring platform 1 and is used to suction the PCB substrate 2 to be glued to the pouring platform 1 to ensure pouring accuracy.

[0061] Wherein, the positioning component can be mechanical positioning or laser positioning. Mechanical positioning can select a positioning pin. When the positioning component is a positioning pin, a pin hole used in conjunction with the positioning pin is opened at the substrate marking point 201 on the PCB substrate 2, and positioning is achieved by inserting the positioning pin into the pin hole.

[0062] Laser positioning can select a laser transmitter. When the positioning component is a laser transmitter, a laser receiver is set at the substrate marking point 201 on the PCB substrate 2. The positioning of the PCB substrate 2 and the steel mesh 3 is achieved through the transmission of laser signals, thereby ensuring the alignment accuracy between the PCB substrate and the steel mesh.

[0063] The vacuum adsorption mechanism includes adsorption holes, a vacuum pump, and an exhaust pipe. The vacuum pump is located inside the pouring platform 1. The surface of the pouring platform 1 is equipped with multiple tiny adsorption holes, each connected to the vacuum pump's exhaust port via an exhaust pipe. When the PCB substrate 2 to be encapsulated is placed on the pouring platform 1, the vacuum pump is activated to create a vacuum between the pouring platform 1 and the PCB substrate 2. This allows the PCB substrate 2 to adhere to the surface of the pouring platform 1, thereby securing its position and ensuring subsequent pouring accuracy.

[0064] Furthermore, the LED sealing device provided by the embodiment of the present invention also includes: a horizontal platform 10. The horizontal platform 10 is arranged below the steel mesh 3 and is symmetrically arranged on the left and right sides of the steel mesh 3. The upper surfaces of the two horizontal platforms 10 are at the same horizontal height, and the structures and dimensions of the two horizontal platforms 10 are completely consistent. The thickness of each horizontal platform 10 is less than the thickness of the PCB substrate 2, and the spacing between the two horizontal platforms 10 is less than the width of the casting platform 1, so that when the casting platform 1 is working, its upper surface contacts the lower surfaces of the two horizontal platforms 10 and is blocked by the horizontal platforms 10, while the upper surface of the PCB substrate 2 is higher than the horizontal platform 10 to facilitate contact with the steel mesh 3.

[0065] A lifting mechanism 101 is provided at the bottom of the pouring platform 1. When the PCB substrate 2 is loaded, the lifting mechanism 101 drives the pouring platform 1 downward so that the PCB substrate 2 to be sealed can be placed on the pouring platform 1. After the PCB substrate 2 is positioned and adsorbed on the pouring platform 1, the lifting mechanism 101 drives the pouring platform 1 upward until it touches the two horizontal platforms 10, thus completing the loading of the PCB substrate 2.

[0066] The second embodiment of the present invention provides an LED encapsulation device. In addition to the first embodiment, the device further comprises a stencil mounting frame 5 and a stencil adjustment mechanism 6. The stencil mounting frame 5 is disposed above the casting platform 1 and is used to mount the stencil 3. The stencil adjustment mechanism 6 is disposed above the casting platform 1 and connected to the stencil mounting frame 5 to adjust the gap between the stencil 3 and the PCB substrate 2 to a first gap.

[0067] Further, if Figure 1 As shown, the steel mesh mounting frame 5 is arranged on the left and right sides above the casting platform 1 and can be moved up and down by a slide rail. The inner sides of the two steel mesh mounting frames 5 are provided with clamps, and the two sides of the steel mesh 3 are respectively clamped in the two clamps and fixed by a fixing assembly.

[0068] A stencil adjustment mechanism 6 is provided above each stencil mounting frame 5. The stencil adjustment mechanism 6 is preferably a pneumatic drive mechanism comprising a cylinder and a piston. The piston is connected to the corresponding stencil mounting frame 5. The cylinder drives the piston up and down, thereby driving the stencil mounting frame 5 and the stencil 3 up and down, thereby adjusting the gap between the stencil 3 and the PCB substrate 2 to the first gap.

[0069] The third embodiment of the present invention provides an LED encapsulation device. In addition to the second embodiment, the device further includes: a scraper mounting frame 8 and a scraper drive mechanism 9. The scraper mounting frame 8 is disposed above the stencil 3 mounting frame and is used to mount the scraper 4. The scraper drive mechanism 9 is disposed on the scraper mounting frame 8 and is used to drive the scraper 4 to move along the length, width, and height of the stencil 3 to adjust the position of the scraper 4 and apply the glue.

[0070] In a preferred but non-limiting embodiment of the present invention, the scraper mounting frame 8 is movably disposed between the two steel mesh adjustment mechanisms 6 via a slide rail, and a scraper 4 is mounted on the bottom of the scraper mounting frame 8 .

[0071] The scraper drive mechanism 9 includes a control system and a z-axis drive mechanism 901, an x-axis drive mechanism 902, and a y-axis drive mechanism 903 connected to the control system. The xyz coordinate axis is centered at the geometric center of the stencil, with the length of the stencil as the x-axis, the width of the stencil as the y-axis, and the height of the stencil as the z-axis.

[0072] Among them, the z-axis drive mechanism 901 includes: a first motor and a screw structure, the first motor is arranged on the scraper mounting bracket 8, the output shaft of the first motor is connected to the screw structure downward along the z-axis direction, and a movable platform is installed on the first screw in the screw structure through a threaded connection. The screw mechanism is driven to rotate by the first motor, thereby driving the movable platform to move in the z-axis direction.

[0073] The x-axis driving mechanism 902 includes: a second motor, a gear transmission mechanism and a second screw rod. The second motor is arranged on the movable platform. The second motor drives the second screw rod to rotate in the y-axis direction through the gear transmission mechanism. The top of the scraper 4 is threadedly connected to the second screw rod through a sleeve, and movement in the x-axis direction is achieved when the second screw rod rotates.

[0074] The y-axis driving mechanism 903 includes a third motor, the driving shaft of the third motor is connected to the scraper moving frame 8 along the y-axis direction, and drives the scraper moving frame 8 to perform linear motion along the slide rail in the y-axis direction, thereby realizing movement in the x-axis direction.

[0075] The coordinate position of the steel mesh marking point 301 is input into the program of the control system, and the control system controls the operation of the z-axis drive mechanism 901, the x-axis drive mechanism 902 and the y-axis drive mechanism 903 to control the moving path of the scraper 4, so as to adjust the gap between the scraper 4 and the steel mesh 3 to the second gap when brushing glue, and move on the surface of the steel mesh 3 to perform the glue brushing operation.

[0076] Among them, the range of the second gap is less than or equal to 0, and preferably less than 0, so that the scraper applies a certain pressure on the surface of the steel mesh, which is conducive to squeezing the packaging glue on the surface of the steel mesh into the interior of each cup groove of the PCB substrate.

[0077] The fourth embodiment of the present invention provides an LED display unit, which is applied to the LED sealing device in any of the above embodiments, including a PCB substrate 2, the PCB substrate 2 includes multiple PCB substrate units 2; the PCB substrate unit 2 includes: a semi-cured sheet 2022 and a PCB circuit board 2021.

[0078] like Figure 5 、 Figure 6 and Figure 7 As shown, the semi-cured sheet 2022 is arranged on the side of the PCB circuit board 2021 having the solder pad 2025, and the semi-cured sheet 2022 is provided with a through hole at the position corresponding to the solder pad 2025. The through hole of the semi-cured sheet 2022 cooperates with the PCB circuit board 2021 to form a cup groove of the PCB substrate 2; the side of the PCB circuit board 2021 away from the semi-cured sheet 2022 is provided with an electrode sheet 2026 for connecting each LED chip component 2024.

[0079] In a preferred but non-limiting embodiment of the present invention, the thickness of prepreg 2022 is greater than that of PCB 2021. If prepreg 2022 is too thick, bubbles may easily form during adhesive printing. If prepreg 2022 is too thin, the adhesive may not fully encapsulate the solder wires. Therefore, the present invention sets the thickness of prepreg 2022 to 0.3mm-0.5mm, while setting the thickness of PCB 2021 to 0.16mm-0.36mm, while minimizing bubbles and ensuring complete encapsulation of the solder wires.

[0080] In the LED display unit provided by the embodiment of the present invention, the thickness of the prepreg is set more reasonably, and the PCB circuit board uses electrode sheets to connect the individual chips of the LED chip assembly, avoiding the setting of extended pins, which easily causes the LED display unit to have positive and negative sides and uneven display problems.

[0081] like Figure 8As shown, the fifth embodiment of the present invention provides an LED encapsulation method, which is applied to the LED encapsulation device in any of the above embodiments, comprising the following steps:

[0082] Step S01: Place the PCB substrate 2 assembled with the LED chip assembly 2024 and ready for glue application with its cup groove facing upward on a casting platform, and ensure that each cup groove of the PCB substrate 2 corresponds to a mesh of the steel mesh;

[0083] Step S02, adjusting the position of the steel mesh so that a first gap is maintained between the steel mesh and the side of the PCB substrate 2 having the cup groove;

[0084] Step S03, pouring the encapsulation glue 2023 onto the surface of the steel mesh from the side of the steel mesh away from the PCB substrate 2;

[0085] Step S04: Use a scraper to repeatedly move on the surface of the steel mesh to brush the encapsulation glue 2023 on the surface of the steel mesh flat, and allow the encapsulation glue 2023 to fully enter the interior of each cup groove through the mesh of the steel mesh to perform glue brushing;

[0086] Step S05 , taking out the PCB substrate 2 after being coated with glue from the casting platform and drying it, thereby completing the LED sealing.

[0087] The above-mentioned LED sealing method changes the traditional LED sealing process from dispensing to brushing. By setting a steel mesh and a scraper, the packaging glue flows from the mesh holes of the steel mesh to the inside of each cup groove of the PCB substrate. Finally, the packaging glue on the surface of the steel mesh is evenly scraped by the scraper, so that the packaging glue fully enters the inside of the cup groove, completing the brushing operation.

[0088] Compared with the dispensing method, the brushing process has low requirements on the viscosity of the glue, large operating space, and high efficiency. It can perform sealing operations on multiple PCB substrate units in batches at the same time, and is especially suitable for sealing operations of small-pitch LED devices.

[0089] Furthermore, the encapsulation glue can flow evenly and smoothly into the cup groove of each PCB substrate unit, improving its consistency and uniformity. The glue application process is easier to control, resulting in better stability and display quality for the LED display unit.

[0090] Wherein, step S01 includes:

[0091] Align the substrate marking point 2021 of the PCB substrate 2 assembled with the LED chip assembly 2024 and ready for glue application with the positioning assembly in the casting platform, and place it on the casting platform with the cup groove facing upwards, so that each cup groove corresponds to a mesh hole; wherein the position of the positioning assembly corresponds to the position of the steel mesh marking point;

[0092] The PCB substrate 2 assembled with the LED chip assembly 2024 is adsorbed onto the surface of the casting platform by a vacuum adsorption mechanism in the casting platform to ensure casting accuracy.

[0093] Step S04 includes:

[0094] The scraper driving mechanism 9 plans the moving path of the scraper according to the position of the substrate marking point 2021 of the PCB substrate 2;

[0095] The scraper is started by the scraper driving mechanism 9 to move on the surface of the steel mesh according to the set moving path until the packaging glue 2023 on the surface of the steel mesh is brushed flat, and the packaging glue 2023 enters the interior of each cup groove from the mesh of the steel mesh for brushing.

[0096] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, they should be understood as "one or more".

[0097] The various steps described in the method implementation methods provided by the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0098] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0099] The above-described embodiments merely represent several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection. It should be noted that a person of ordinary skill in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the appended claims.

Claims

1. An LED sealing device, characterized in that: include: Casting platform, used to set the PCB substrate of the LED display unit; The PCB substrate has a cup groove on one side away from the casting platform, and the LED chip assembly is assembled inside the cup groove and is in a state to be sealed; The steel mesh is arranged above the pouring platform and maintains a first gap with the PCB substrate during the sealing process. The steel mesh is provided with a plurality of mesh holes running through the upper and lower parts of the steel mesh. During the sealing process, each mesh hole corresponds to a cup groove, and is used to guide the encapsulation glue into the corresponding cup groove. The scraper is used to move on the side of the steel mesh away from the PCB substrate to fully squeeze the packaging glue from the mesh holes of the steel mesh into the inside of each cup groove to seal the LED chip assembly.

2. The LED sealing device according to claim 1, wherein: The spacing between adjacent meshes of the steel mesh is the same as the spacing between adjacent cup grooves of the PCB substrate, and the size of the mesh is larger than the size of the corresponding cup groove.

3. The LED sealing device according to claim 2, characterized in that: The mesh holes are square holes or circular holes, and the cup grooves are circular grooves; The center line of each mesh coincides with the center line of the corresponding cup groove.

4. The LED encapsulation device according to any one of claims 1 to 3, characterized in that: The scraper is a plastic scraper having a bidirectional blade.

5. The LED sealing device according to any one of claims 1 to 3, characterized in that: Also includes: The pouring platform is provided with a vacuum adsorption mechanism and a positioning component; The positioning assembly is arranged on the working surface of the casting platform and corresponds to the marking point of the steel mesh, and is used to align with the substrate marking point of the PCB substrate during sealing and to make the cup groove of the PCB substrate correspond to the mesh of the steel mesh one by one; The vacuum adsorption mechanism is arranged on the working surface of the pouring platform, and is used to adsorb the PCB substrate to be brushed with glue on the pouring platform to ensure the pouring accuracy.

6. The LED sealing device according to any one of claims 1 to 3, characterized in that: Also includes: The steel mesh mounting frame is set above the pouring platform and is used to install the steel mesh; The steel mesh adjustment mechanism is arranged above the casting platform and connected to the steel mesh mounting frame, and is used to adjust the gap between the steel mesh and the PCB substrate to the first gap.

7. The LED sealing device according to claim 5, characterized in that: Also includes: The scraper mounting frame is arranged above the steel mesh mounting frame and is used to install the scraper; The scraper drive mechanism is arranged on the scraper mounting frame and is used to drive the scraper to move along the length, width and height of the steel mesh to adjust the position of the scraper and apply glue.

8. An LED display unit, applied to the LED sealing device according to any one of claims 1 to 7, characterized in that: Including PCB substrate; The PCB substrate includes a plurality of PCB substrate units; the PCB substrate units include: a prepreg and a PCB circuit board; The prepreg is arranged on a side of the PCB circuit board having a pad, and a through hole is provided at a position of the prepreg corresponding to the pad. The through hole of the prepreg cooperates with the PCB circuit board to form a cup groove of the PCB substrate; An electrode sheet for connecting each LED chip assembly is provided on a side of the PCB circuit board away from the prepreg; The thickness of the prepreg is greater than that of the PCB circuit board.

9. The LED sealing device according to claim 8, characterized in that: The thickness of the prepreg is 0.3 mm to 0.5 mm, and the thickness of the PCB circuit board is 0.16 mm to 0.36 mm.

10. An LED encapsulation method, applied to the LED encapsulation device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Place the PCB substrate assembled with LED chip components and ready for glue application with the cup groove facing upwards on the casting platform, and make sure that each cup groove of the PCB substrate corresponds to a mesh of the steel mesh; Adjust the position of the steel mesh so that a first gap is maintained between the steel mesh and the side of the PCB substrate having the cup groove; Pour the packaging glue onto the surface of the steel mesh from the side away from the PCB substrate; Use a scraper to move repeatedly on the surface of the steel mesh to brush the encapsulation glue on the surface of the steel mesh flat, and allow the encapsulation glue to fully enter the interior of each cup groove from the mesh of the steel mesh to brush the glue; Remove the PCB substrate from the casting platform after applying glue and dry it to complete the LED sealing.

11. The LED encapsulation method according to claim 10, characterized in that: Place the PCB substrate assembled with LED chip components and ready for glue application with the cup groove facing upwards on the casting platform, and make each cup groove of the PCB substrate correspond to a mesh of the steel mesh, including: Align the substrate marking points of the PCB substrate assembled with the LED chip assembly and ready for glue application with the positioning assembly in the casting platform, and place it on the casting platform with the cup groove facing upwards so that each cup groove corresponds to a mesh hole; the position of the positioning assembly corresponds to the position of the steel mesh marking points; The PCB substrate assembled with the LED chip components is adsorbed on the surface of the casting platform through the vacuum adsorption mechanism in the casting platform to ensure the casting accuracy.

12. The LED encapsulation method according to claim 10, characterized in that: Use a scraper to move repeatedly on the surface of the steel mesh to brush the encapsulation glue on the surface of the steel mesh flat, and make the encapsulation glue fully enter the interior of each cup groove from the mesh of the steel mesh to brush the glue, including: The scraper driving mechanism plans the moving path of the scraper according to the position of the substrate marking point of the PCB substrate; The scraper is started by the scraper drive mechanism to move on the surface of the steel mesh according to the set moving path until the encapsulation glue on the surface of the steel mesh is brushed flat, and the encapsulation glue enters the inside of each cup groove from the mesh of the steel mesh for brushing.

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